This invention relates to a mold press for the production of molded workpieces of rubber or plastic material employing a two-part mold and a cleaning device in combination with the mold press for cleaning a mold surface and for ejecting the workpieces. The mold press and attached cleaning device may be disposed upright so that the two mold halves may be separated horizontally, or may be disposed horizontally so that the mold halves may be vertically separated. A cleaning brush of the device is capable of adjustment parallel to the mold surface, and can extend in between the two separated mold halves.
A mold press with a cleaning device thereon is disclosed, for example, in West German Pat. No. 21 33 748. This cleaning device has a roller brush which can be rolled along the mold surface of one mold half, and may then be rolled along the mold surface of the opposite mold half by means of a horizontal guide, for cleaning of the mold surfaces thereby being effected and for ejecting the molding workpieces. However, this device suffers from the disadvantage in that only a portion of the mold surface can be cleaned because the roller, together with its roller support, must be smaller than the space between the two upper centering pins which are employed for centering the mold halves when closed. Thus, a portion of the mold surface becomes inaccessible for cleaning, and/or the mold surface cannot have mold pockets since they cannot be cleaned. Moreover, cleaning cannot be effectively carried out with a brush roller which moves up and down with a rolling motion of the brush. And,a roller brush of this type is incapable of protruding into the mold pockets such that these pockets may never be cleaned with this type of roller brush. The centering pins of the mold halves also present obstacles for the roller brush.
A mold press having horizontally disposed molds for the production of molded plastic workpieces, is likewise generally known, as for example disclosed in British Pat. No. 581,642. This apparatus includes a horizontal continuous conveyor which serves several work stations. The halves of the two-part mold are connected by hinges, and are transported on the conveyor. In an open position, the lower mold half rests on the conveyor and the upper mold half lies at a 90.degree. angle (or vertical) to the conveyor.
For cleaning the mold halves, two stations are required, one for the horizontal mold half and one for the upright mold half. The cleaning device for the horizontal mold half includes a rod having at its end a cross support for four rotating cleaning brushes which clean the mold pockets. The second cleaning station also has such a rod, at the end of which a horizontal rod with cleaning brushes for the vertical mold half is arranged.
Apart from the two cleaning stations, the apparatus also has two removal stations for the workpieces, each also with a rod. The latter is provided with a suction bell.
The cleaning and removal stations are essentially the same in that the rod for each is connected to a piston rod of an operating cylinder such that the rod can be rotated through 90.degree. from the working position.
The disadvantage with such an apparatus is that two separate cleaning and two separate removal stations are required, thereby significantly adding to the cost. Moreover, no optimum cleaning of the surfaces of the mold halves is possible since the brushes can only be inserted between the mold halves at a certain position, and the cleaning brushes cannot be pivoted for extension into the mold pockets. The cleaning of the entire mold surface is therefore not made possible. This apparatus is only employed for molds which are hinged together, and the cleaning as well as the injection operations are not timed to the operations of an injection molding machine.